Method and system for switching a functionality of a liner expansion tool

ABSTRACT

The functionality of a downhole tubular expansion tool is switched by: -providing the unexpanded tubular with an oversized section ( 7 ) having a larger internal width than other (non-oversized) sections of the unexpanded tubular ( 6 );-providing the expansion tool with a control sub ( 1 ) comprising a trigger assembly ( 2 ) that is pushed outward within the oversized section and thereby switches the functionality of the tool, for example by contracting or expanding a collapsible expansion cone and/or opening a valve.

BACKGROUND OF THE INVENTION

The invention relates to a method and system for switching a functionality of an expansion tool for expanding a well liner, casing or other well tubular downhole in an underground wellbore.

Known downhole expansion methods and systems are disclosed in WO2012104257 and U.S. Pat. Nos. 7,497,255, 7,640,976 and 7,493,946.

In these known systems an expansion cone is moved downhole through an initially unexpanded well liner, casing or other tubular to expand the tubular.

It is known to switch the functionality of the expansion tool by mechanically pulling and/or rotating the drill string from which the expansion tool is suspended and/or by stepwise changes of the fluid pressure within the interior of the drill string, for example for expanding or retracting a collapsible expansion cone and/or for opening or closing a valve.

A disadvantage of the known systems is that often the location of the expansion cone within the tubular is not exactly known, whereas it may be desired to switch the functionality of the expansion tool at a predetermined location along the length of the expanded tubular.

There is a need for an improved method and system for switching the functionality of an expansion tool that overcomes the drawbacks of the known systems.

SUMMARY OF THE INVENTION

In accordance with the invention there is provided

a method for switching a functionality of a downhole tubular expansion tool that is longitudinally moved through an initially unexpanded well tubular to expand at least part of the length of the tubular, the method comprising:

-   -   providing the unexpanded tubular with an oversized section         having a larger internal width than other sections of the         unexpanded tubular;     -   providing the expansion tool with a control sub comprising a         trigger assembly that is pushed outward within the oversized         section and thereby switching the functionality of the tool.

The unexpanded tubular may comprise a plurality of oversized sections with different lengths, and the expansion tool may comprise a plurality of control subs with expandable collet segments having corresponding lengths, thereby switching the functionality of the expansion tool at different longitudinally spaced locations along the length of the unexpanded tubular.

In accordance with the invention there is furthermore provided a system for switching a functionality of a downhole tubular expansion tool that is longitudinally movable through an initially unexpanded well tubular to expand at least part of the length of the tubular, the system comprising

a control sub comprising a trigger assembly that is pushed outward within an oversized section of an unexpanded well tubular and thereby switching the functionality of the tool.

The expansion tool may comprise a collapsible expansion cone and/or a valve, which is switched to a different operating mode by the trigger assembly and the trigger assembly may comprise a trigger sleeve and expandable collet segments which axially move the sleeve relative to other parts of the expansion tool when the collet segments expand within the oversized section.

These and other features, embodiments and advantages of the expansion method and tool according to the invention are described in the accompanying claims, abstract and the following detailed description of non-limiting embodiments depicted in the accompanying drawings, in which description reference numerals are used which refer to corresponding reference numerals that are depicted in the drawings.

Similar reference numerals in different figures denote the same or similar objects. Objects and other features depicted in the figures and/or described in this specification, abstract and/or claims may be combined in different ways by a person skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show a control sub according to the invention when it moves into, through and out of an oversized section of an initially unexpanded well tubular.

DETAILED DESCRIPTION OF THE DEPICTED EMBODIMENTS

FIGS. 1 and 2 show a control sub according to the invention that changes a functionality of the expansion tool string at a specified location in the expandable liner.

Use is made of a change in internal diameter of the expandable liner to trigger the control action of a control sub (2) in the expansion tool string, which is located ahead of the expansion cone or cones as illustrated in FIG. 1A. The control sub (1) comprises a segmented trigger sleeve (2), which is loaded by a spring (3) via a hydraulic valve (4). The spring force causes the trigger sleeve segments to move over ramps (5) outwards toward the inner diameter of the unexpanded liner (6).

During expansion of the liner the trigger sleeve slides against the inner surface of the initially unexpanded liner. When the expansion tool string reaches an oversized section of liner (7) with an increased inner diameter, the trigger sleeve (2) is pushed further outward over the ramps, as illustrated in FIG. 1B which open the hydraulic valve such that a hydraulic connection is made between the bore of the expansion tool string and a fluid channel (8).

When the total length of the trigger sleeve has entered the over-sized section of the liner, its saw tooth profile jumps over the ramps in the body of the control sub as illustrated in FIG. 1C. Subsequently the trigger sleeve collapses when it enters into the liner section with nominal inner diameter as illustrated in FIG. 1D.

Alternatively the control sub concept may also be used to take a mechanical action when the expansion tool sting has reached a specific location in the liner.

A schematic drawing of such a mechanical control sub is shown in FIG. 2 a.

A collet (10) is locked in a groove in the body of the tool string by a collet sleeve (11). This sleeve is pushed by a spring (3) in the direction of the trigger sleeve but the ramps and the liner with nominal inner diameter prevent sliding of the collet sleeve. When the trigger sleeve enters the oversized section of the liner the collet sleeve starts sliding as illustrated in FIG. 2B. When the full length of the trigger sleeve has entered into the oversized section of the liner the collet (10) is released from the groove (9) in the tool string body and the trigger sleeve jumps the ramp (5) (FIG. 2c ). After this it can collapse and enter into the liner with nominal inner diameter (FIG. 2d ).

The release and movement of the collet may be used to mechanically change the functionality of the expansion tool string.

The hydraulic control sub (2) may be used e.g. to hydraulically collapse a bell cone by inserting an oversized section in the expandable liner at the top of the bell section. The collapse action of the bell will only occur when the trigger sleeve is in the oversized liner section or has passed this section. At any earlier stage of the liner installation process pressure pulses in the bore of the expansion tool string may be used for other actions without affecting the collapse action of the bell cone.

The control sub concept can be designed to respond only to an oversized liner section exceeding a specific length. When the trigger sleeve encounters an oversized liner section with a length less than that of the trigger sleeve it will not respond.

Consequently multiple control subs may be installed in the expansion tool string, which respond to specific oversized section lengths at various locations in the liner.

Therefore, the method, system and/or any products according to present invention are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein.

The particular embodiments disclosed above are illustrative only, as the present invention may be modified, combined and/or practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein.

Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below.

It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined and/or modified and all such variations are considered within the scope of the present invention as defined in the accompanying claims.

While any methods, systems and/or products embodying the invention are described in terms of “comprising,” “containing,” or “including” various described features and/or steps, they can also “consist essentially of” or “consist of” the various described features and steps.

All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values.

Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.

Moreover, the indefinite articles “a” or “an”, as used in the claims, are defined herein to mean one or more than one of the element that it introduces.

If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be cited herein by reference, the definitions that are consistent with this specification should be adopted. 

1. A method for switching a functionality of a downhole tubular expansion tool that is longitudinally moved through an initially unexpanded well tubular to expand at least part of the length of the tubular, the method comprising: providing the unexpanded tubular with an oversized section having a larger internal width than other sections of the unexpanded tubular; providing the expansion tool with a control sub comprising a trigger assembly that is pushed outward within the oversized section and thereby switching the functionality of the tool.
 2. The method of claim 1, wherein the trigger assembly is spring, hydraulically and/or otherwise resiliently loaded and expanded within the oversized section and collapsed in the other sections of the unexpanded tubular.
 3. The method of claim 1, wherein the expansion tool comprises a collapsible expansion cone and/or a valve, which is switched to a different operating mode by the trigger assembly.
 4. The method of claim 3, wherein the trigger assembly comprises a trigger sleeve and expandable collet segments which axially move the sleeve relative to other parts of the expansion tool when the collet segments expand within the oversized section.
 5. The method of claim 4, wherein the unexpanded tubular comprises a plurality of oversized sections with different lengths, and the expansion tool comprises a plurality of control subs with expandable collet segments having corresponding lengths, thereby switching the functionality of the expansion tool at different longitudinally spaced locations along the length of the unexpanded tubular.
 6. A downhole tubular expansion tool that is longitudinally movable through an initially unexpanded well tubular to expand at least part of the length of the tubular, the downhole tubular expansion tool comprising a control sub comprising a trigger assembly that is pushed outward within an oversized section of an unexpanded well tubular and thereby switching the functionality of the tool.
 7. The expansion tool of claim 11, wherein the trigger assembly is spring, hydraulically and/or otherwise loaded and configured to be expanded in the oversized section and to be collapsed in other sections of the unexpanded tubular.
 8. The expansion tool of claim 11, wherein the expansion tool comprises a collapsible expansion cone and/or a valve, which is switched to a different operating mode by the trigger assembly.
 9. The expansion tool of claim 8, wherein the trigger assembly comprises a trigger sleeve and expandable collet segments which axially move the sleeve relative to other parts of the expansion tool when the collet segments expand within the oversized section.
 10. The expansion tool of claim 11, wherein the unexpanded tubular comprises a plurality of oversized sections with different lengths, and the expansion tool comprises a plurality of control subs with expandable collet segments having corresponding lengths, thereby switching the functionality of the expansion tool at different longitudinally spaced locations along the length of the unexpanded tubular.
 11. A system comprising an unexpanded tubular with an oversized section having a larger internal width than other sections of the unexpanded tubular; and a downhole tubular expansion tool that is longitudinally movable through the unexpanded well tubular to expand at least part of the length of the tubular, wherein downhole tubular expansion tool has a switchable functionality and comprises a control sub comprising a trigger assembly that is pushed outward within the oversized section of the unexpanded well tubular to thereby switch the functionality of the tool.
 12. The system of claim 11, wherein the trigger assembly is spring, hydraulically and/or otherwise loaded and configured to be expanded in the oversized section and to be collapsed in other sections of the unexpanded tubular.
 13. The system of claim 11, wherein the expansion tool comprises a collapsible expansion cone and/or a valve, which is switched to a different operating mode by the trigger assembly.
 14. The system of claim 13, wherein the trigger assembly comprises a trigger sleeve and expandable collet segments which axially move the sleeve relative to other parts of the expansion tool when the collet segments expand within the oversized section. 